Need help on a Schematic...

[Boricua SS]

ok group.... quick question for all of you...

you all know the story behind the beaSSt.... that being said, i think i might want to monitor some things by way of gauges... all i have right now is an A/F ratio gauge (air to fuel).. it is a narrowband and not a wideband... so i dont need to weld in a new bung to make the gauge functional..

my question is the signal wire coming from the gauge... it has red and balck for power and ground.. but then the purple wire for the signal to make the gauge work... here is the instructions detail for the purple/violet wire...

Violet Wire: Connect to oxygen sensor signal wire. Connect to
vehicle wiring harness, not oxygen sensor since some oxygen
sensors use shielded wire.

so there inlies the question... does anyone know what wire is the signal wire coming off the PCM? i downloaded Moosemans manual for the 2007 TBSS and i swear its like reading chinese to me so if someone knows how to read the schematic, or knows the exact wire to tap to give the gauge its signal... i would greatly appreciate it...

heres the link to the whole instructional page or the gauge...

http://www.autometer.com/productPDF/0837L.pdf

 

[kardain]

Sorry, I don't have the schematics for 07, but if the front o2 sensor is a heated one (4 wire plug), there is always something like this.....

http://www.wbodystore.com/prestademo/harnesses-adapters/20-air-fuel-gauge-pigtail.html

 

[Boricua SS]

very interesting man... thx for that info...

would there be a difference since its for the 3800 V6 of the WBody grand prix.. or is that like a universal thing? i can call the dealership tomorrow and have them look for me since the body is off the frame lol...

but then there inlies another issue... which O2 would i use... i think the SS has 4? or maybe just 2... i know Bank 1 is the driverside before the cat i do believe... this is becoming a headache lol... at least the gauge was free

 

[kardain]

Use bank 1, sensor 1

The only real difference is the wire length from the OEM connector to the sensor. GM uses the same 4 wire plug for the heated o2's.... At least for 05 (the last year I have available for shop manuals) all 4 O2 sensors in the 5.3 are the same as the one in the w-body... 06+ should be the same as 05.... The pics on rockauto show the same plug design.

 

[MAY03LT]

I thought they were for either of the pre-cat HO2S. Not too familiar with installing these but I'm fluid with the diagrams. I think the last guy who did one got the signal at the O2 because it was easier then getting to the PCM.

Bank 1 upstream High is purple/white stripe
Bank 2 upstream High is purple

 

[Boricua SS]

Use bank 1, sensor 1

The only real difference is the wire length from the OEM connector to the sensor. GM uses the same 4 wire plug for the heated o2's.... At least for 05 (the last year I have available for shop manuals) all 4 O2 sensors in the 5.3 are the same as the one in the w-body... 06+ should be the same as 05.... The pics on rockauto show the same plug design.

yea im lookin at rockautop right now (great minds think alike

so it looks like this little pigtail adapter is the key for me?

I thought they were for either of the pre-cat HO2S. Not too familiar with installing these but I'm fluid with the diagrams. I think the last guy who did one got the signal at the O2 because it was easier.

Bank 1 upstream High is purple/white stripe
Bank 2 upstream High is purple

thx for chiming in Drew... i was hoping you or roadie would.. i sent him a PM and he's pretty busy right now and advised i make a thread...

so is that the purple with white stipe wire coming off the PCM? if so, which of the 3 harness' would that wiire be located at?

 

[MAY03LT]

so is that the purple with white stipe wire coming off the PCM? if so, which of the 3 harness' would that wiire be located at?

That one is in C2 (the black connector) pin 3. BUT, there are 2 other purple/whites in that connector. One is for bank 1 post-cat HIGH signal (pin 4), the other is for coil #8 control(pin 17). If the V8s connectors are like the I6s, you can't really see where they go into the connector. If that's the case, a continuity test (with C2 unplugged) between each of the 3 purple/white wires where they come out of the connector and the purple/white wire at the bank 1 upstream O2 would be the way to find the correct one.

 

[Boricua SS]

That one is in C2 (the black connector) pin 3. BUT, there are 2 other purple/whites in that connector. One is for bank 1 post-cat HIGH signal (pin 4), the other is for coil #8 control(pin 17). If the V8s connectors are like the I6s, you can't really see where they go into the connector. If that's the case, a continuity test (with C2 unplugged) between each of the 3 purple/white wires where they come out of the connector and the purple/white wire at the bank 1 upstream O2 would be the way to find the correct one.

hmmmm... looks like i'll be having to dig around then

i got a PM on tbssowners as well from someone who has installed a A/F gauge... he said there is a signal wire off the O2 sensor... he's digging up his thread to lett me know... and since i'll have the connector apart anyway to install my e-fans, i wonder how easy it would be to see the purrple/white wire in pin 3,4,and 17...

im still keepin my ffingers crossed on that pigtail adapter.. soo much easier to do it that way lol..

Edit:... jus got confirmation that that pigtail adapter will work on the SS...

Thx for tip kardain and thx for the info Drew...

 

[MAY03LT]

I wonder if he just grabbed purple white at the O2. Like I said, in ours, the wiring just disappears before it goes into the connector. When I have had to get at a specific pcm wire that has other wires of the same color in the same connector I just do the continuity test. Hopefully you find an easier way!